1. Field of the Invention
The present invention relates to a film formation source material, film formation method, and film formation apparatus for forming a metal oxide film, such as an HfO2 film, on a target object, such as a semiconductor wafer, and particularly a technique utilized for the filed of semiconductor processes. The term “semiconductor process” used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target object, such as a semiconductor wafer or a glass substrate used for an FPD (Flat Panel Display), e.g., an LCD (Liquid Crystal Display), by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target object.
2. Description of the Related Art
In recent years, owing to the demands for increased integration and operation speed of LSIs, the design rule of semiconductor devices for constituting LSIs has increasingly been miniaturized. Along with this trend, CMOS devices needs to have a thinner gate insulating film, and thus the material of gate insulating films are required to have a higher dielectric constant. Further, DRAMs are required to have a capacitor with a higher capacity and a dielectric film with a higher dielectric constant.
On the other hand, flash memories are required to improve the reliability, so the insulating film interposed between the control gate and floating gate thereof needs to have a higher dielectric constant.
As a high dielectric constant material applicable to this purpose, a hafnium oxide (HfO2) film has been examined. Conventionally, a hafnium oxide film is formed by CVD (MOCVD) using an organic metal source material, and tetrakisethylmethylamino hafnium (TEMAH) is used as a source material gas in general (for example, see Jpn. Pat. No. 3,698,163). TEMAH is highly reactive with oxidizing gases and easy to use because this substance is liquid at room temperature (25° C.)